import React, {useEffect, useState, useRef, useContext} from "react";
import {useCreatePath, usePaths} from "../utils/queries/path-queries";
import { useQueryClient } from "@tanstack/react-query";
import { Plus } from "lucide-react";
import "./PathManager.css";
import {fetch_} from "../utils/request-utils";
import {ConfigContext} from "../ConfigProvider";
import { Input } from "./ui/input";
import { Button } from "./ui/button";
import { Spinner } from "./ui/misc";


const PathManager = ({ currentPathId = 1, onPathChange }) => {
    const [currentFullPath, setCurrentFullPath] = useState([{ name: "Root", id: 1 }]);
    const [searchTerm, setSearchTerm] = useState("");
    const [dropdownActive, setDropdownActive] = useState(false);

    const inputRef = useRef();

    const queryClient = useQueryClient();
    const { data: subPaths, isLoading: isSubPathsLoading, error: subPathsError } = usePaths(currentPathId);
    const createPath = useCreatePath();
    const config = useContext(ConfigContext).config;


    const buildFullPath = async (pathId) => {
        const path = [];
        let current_id = pathId;
        while (current_id) {
            try {
                const pathData = await queryClient.fetchQuery({
                    queryKey: ["path", current_id],
                    queryFn: () => fetch_(`${config.BACKEND_HOST}/api/path/${current_id}`)
                });
                if (!pathData) break;
                path.unshift({ name: pathData.name, id: pathData.id });
                current_id = pathData.parent_id;
            } catch (error) {
                console.error(`Failed to fetch path with id ${current_id}:`, error);
                break;
            }
        }
        return path;
    };

    useEffect(() => {
        const init = async () => {
            const path = await buildFullPath(currentPathId);
            setCurrentFullPath(path);
        };
        init();
    }, [currentPathId, queryClient]);

    const handlePathClick = (pathId, pathIndex) => {
        const newPath = currentFullPath.slice(0, pathIndex + 1);
        setCurrentFullPath(newPath);
        onPathChange(pathId);
    };

    const handleSubPathSelect = (subPath) => {
        const updatedPath = [...currentFullPath, { name: subPath.name, id: subPath.id }];
        setCurrentFullPath(updatedPath);
        onPathChange(subPath.id);
        setSearchTerm("");
        setDropdownActive(false);
    };

    const handleAddDirectory = () => {
        if (!searchTerm.trim()) {
            alert("Directory name cannot be empty.");
            return;
        }

        createPath.mutate(
            { name: searchTerm.trim(), parent_id: currentPathId },
            {
                onSuccess: (newDir) => {
                    queryClient.setQueryData({queryKey: ["path", newDir.id]}, newDir);
                    queryClient.invalidateQueries({queryKey: ["paths", currentPathId]});
                    setSearchTerm("");
                    alert("Directory created successfully.");
                },
                onError: (error) => {
                    console.error("Failed to create directory:", error);
                    alert("Failed to create directory.");
                },
            }
        );
    };

    const handleInputFocus = () => setDropdownActive(true);

    const handleInputBlur = () => {
        setTimeout(() => setDropdownActive(false), 150);
    };

    const filteredSubPaths = subPaths
        ? subPaths.filter((path) =>
            path.name.toLowerCase().includes(searchTerm.toLowerCase())
        )
        : [];

    const handleKeyDown = (e) => {
        if (e.key === "Enter") {
            e.preventDefault();
            handleAddDirectory();
        }
    };

    return (
        <div className="path-manager space-y-3">
            <div className="flex flex-wrap items-center gap-1.5">
                {currentFullPath.map((path, index) => (
                    <button
                        type="button"
                        key={path.id}
                        className="rounded-md border border-border bg-surface/60 px-2 py-1 font-mono text-xs text-primary transition-colors hover:border-primary/60"
                        onClick={() => handlePathClick(path.id, index)}
                    >
                        {path.name + "/"}
                    </button>
                ))}
            </div>

            <div className="path-manager-body">
                <div className="flex items-center gap-2">
                    <div className="relative flex-1">
                        <Input
                            ref={inputRef}
                            className="h-8 text-xs"
                            type="text"
                            placeholder="Search or create directory"
                            value={searchTerm}
                            onChange={(e) => setSearchTerm(e.target.value)}
                            onFocus={handleInputFocus}
                            onBlur={handleInputBlur}
                            onKeyDown={handleKeyDown}
                        />
                        {dropdownActive && (
                            <div className="path-manager-dropdown absolute left-0 top-full z-20 mt-1 w-full overflow-y-auto rounded-md border border-border bg-card shadow-glow">
                                {filteredSubPaths.length > 0 ? (
                                    filteredSubPaths.map((subPath) => (
                                        <button
                                            type="button"
                                            key={subPath.id}
                                            className="block w-full px-3 py-2 text-left text-xs text-foreground transition-colors hover:bg-accent"
                                            onClick={() => handleSubPathSelect(subPath)}
                                        >
                                            {subPath.name}
                                        </button>
                                    ))
                                ) : (
                                    <div className="px-3 py-2 text-xs text-muted-foreground">
                                        No matches found
                                    </div>
                                )}
                            </div>
                        )}
                    </div>
                    <Button
                        type="button"
                        size="sm"
                        onClick={handleAddDirectory}
                        disabled={isSubPathsLoading || !searchTerm.trim()}
                    >
                        <Plus className="h-4 w-4" /> Create "{searchTerm}"
                    </Button>
                </div>
                {isSubPathsLoading && <Spinner label="Loading paths" />}
                {subPathsError && (
                    <p className="font-mono text-xs text-destructive">
                        Error loading subdirectories.
                    </p>
                )}
            </div>
        </div>
    );
};

export default PathManager;